Joseph osborne whiteley



Patented (Bat. 10, 1922.

UNITED STATES PATIENT OFFICE.

JOSEPH OSBORNE WHITELEY, OF YORK, PENNSYLVANIA, ASSIGNOB TO THE DENTISTS SUPPLY COMPANY, A CORPORATION OF NEW YORK.

ALLOY.

N Drawing.

T 0 all whom it may concern Be it known that I, Josnrn OsnoRNn WInrnLnY, a citizen of the United States, and. resident of York, county of York, and State of Pennsylvania have invented an Improvement in Alloys, of which the following is a specification.

The object of my invention is to produce a new alloy of precious metals and more par ticularly of gold and platinum which will provide an alloy which will have harder characteristics than either of these metals of which it is composed and at the same time will retain its ductility sufliciently to enable the metal to be mechanically handled, such as in drawing it into small tubes suitable for hypodermic syringe needles and other arti cles of commerce where noncorrosiveness, coupled with relative cheapness, are required.

Heretofore hypodermic needles have been made of platinum and while reasonably satisfactory, they are objectionable in that if overheated they become too ductile to avoid bending under rough usage. I-Iypodermic needl s made from my new alloy of gold and platinum in the proportions hereinafter stated have a hardness which gives them resiliency without danger of bending and at the same time they may be heated to a high temperature without losing their hardness and resiliency and for that reason the alloy is especially useful in articles requiring these properties, and reference is made to the hypodermic needle as an example of utility of my improved alloy.

Aside from the improved resiliency, hardness and resistance to the softening tendency of heat, a hypodermic needle formed of my improved alloy will retain its sharpness for a greater length of time and the point may be made sharper than what would result with the use of platinum alone. By careful experiment and testing, I have found that an addition of from 20% to 35% of gold to 65% to 80% of platinum, respec- Lively, forms, when melted together, in a crucible composed of lime, magnesia and zirconia by use of the oxyhydrogen flame by way of example, an alloy which. is normally hard and at the same time is not brittle, its

Application filed June 29, 1920. Serial No. 392,665.

ductility being such that it may be drawn or worked into various forms, among which is the fine tubular form suitable for hypodermic needles. Aside from the use of the oxyhydrogen flame as the important means of producing the high temperature necessary for heating the lime crucible, above referred to, I have found that the desired temperature may be satisfactorily secured by the employment of an electric furnace, preferably of the induction type. I have also found that the alloy thus produced may be subjected to a high temperature without losing its hardness or resiliency.

In practice, I have preferred to form the alloy, especially for hypodermic needles, of 30% of gold to 70% of platinum. By employing a large percentage of gold, the cost of the alloy is relatively less than the cost of platinum, especially where the price of platinum is relatively greater than the price of gold, as it has been for many years. The alloy is homogeneous in composition, as gold and platinum thoroughly alloy themselves one to the other and the presence of the relatively large quantity of gold in the alloy makes the same more easily soldered than would be possible with platinum alone or when associated as an alloy with other hardening elements, such as iridium.

Aside from the desirable properties of the alloy, with particular reference to its hardness and resiliency while maintaining sufficient ductility to enable it to be properly worked or wrought into desired forms, the special property which enables it to be heated to high temperatures without losing its hardness and resiliency and hence without materially increasing its ductility is of the utmost importance, and provides a characteristic quality to my improved alloy which does not exist in any other alloy of platinum as far as I am aware.

While my invention is particularly di rected to an alloy formed of gold and platinum alone in substantially the proportions stated, I do not consider that a very slight addition of other precious metals, such as iridium for example, would be a deviation from my invention, broadly considered, pro- 100 vided such addition did not interfere with the production and maintenance of the special qualities which I have found embodied in my special alloy in its preferred 5 pro ortions.

ters Patent, is: 1. An alloy of gold a nd platinum in which the gold content is from 20% to 35% of the 10 a Whole.

2. An article of manufacture formed of a drawn alloy of gold and platinum having the proportion of the gold approximately 20% to 35% of the Whole.

In testimony of which invention I hereunto set my hand. I

JOSEPH OSBORNE WHITELEY. 

